Generate Apple app icon sizes from a larger image

Generate Apple App Icon sizes from a larger image.md

Generate Apple App Icon sizes from a larger image

ruby generate_app_icon_sizes.rb path_to_large_image

generate_app_icon_sizes.rb

#!/usr/bin/env ruby

require 'bundler/setup'
require 'mini_magick'

class GenerateAppIconSizes

  def initialize(file_path, base_file_name)
    return puts 'You need an app icon file path to start from' unless file_path.length > 0
    `mkdir tmp`
    @file_path = file_path
    @base_file_name = base_file_name || 'AppIcon'
    process_size(29, 29)
    process_size(40, 40)
    process_size(60, 60, true, false)
    process_size(76, 76, false)
  end

  def process_size(width, height, include_3x=true, include_1x=true)
    file_name = "#{@base_file_name}#{width}x#{height}"
    puts "generating #{file_name}"
    img = MiniMagick::Image.open(@file_path)
    img.format 'png'
    if include_3x
      # make @3x version first
      img.resize "#{width*3}x#{height*3}"
      img.write "tmp/#{file_name}@3x.png"
    end
    # make @2x version second
    img.resize "#{width*2}x#{height*2}"
    img.write "tmp/#{file_name}@2x.png"
    # make reg version last
    if include_1x
      img.resize "#{width}x#{height}"
      img.write "tmp/#{file_name}.png"
    end
  end

end

GenerateAppIconSizes.new(ARGV[0], ARGV[1])